How I use it: search engines.

The strength and at the same time the challenge of the Internet is the vast amount of free information available, which continues to expand exponentially. The surface web is the part of the web most people browse and although large, covers only a fraction of the available information in the World Wide Web. Even just using the surface web, it is impossible to find information without either knowing the Uniform Resource Locator (URL) for a specific web page or using a search engine. Search engines such as Google or Alta Vista are programs designed to retrieve data published on the web. They work by sending out spiders or webcrawlers to fetch as many documents relating to keywords. The information on the Internet sites is then coded by a subsequent program and indexes it in a database (like filing books or journals in a library). These program using metatags created using HyperText Markup Language (html) related to keywords to ensure the data is retrievable when a specific search is requested by someone using the search engine. Algorithms are used to direct the search and rank the information with the assumption that increased frequency and location of keywords have higher relevance in a search than those with keywords being used less frequently or not in a prime location on the website. Metasearch engines such as Dogpile and Metacrawler are a special type of search engine that don’t create their own database but are programmed to search other search engine databases to provide broader searches. It should be noted that some search engines such as Google and Northern Light do not allow metasearching of their databases. When using search engines, it is useful to know what databases they are searching to ensure that the relevant data you require is accessible through that search engine. The deep web refers to the content that is contained in searchable databases but can’t be accessed by the spiders used by normal search engines. These include library databases, commercial andspecialized technical databases that may be indexed by people attaching specific metadata tags. Some metasearch engines such as Complete Planet and Pipl (which specifically searches for people on the deep web) are now overcoming these technological barriers to provide deeper searches in response to a query.